The idea of working with film vets Michael Douglas, Morgan Freeman, Kevin Kline and Robert De Niro was "scary," admits Last Vegas director Jon Turteltaub.

"There's a weird balance between being excited to work with legendary actors and being so excited that you can't actually do your job,'' he says. "You don't want to be the guy who's working with someone and also asking for their autographs, because that just makes you a loser."

But Turteltaub, who also directed 1993 comedy Cool Runnings and two National Treasure movies, managed to survive it. Now, the finished product, Last Vegas, featuring the four stars as childhood friends who head to Sin City for one last hurrah, hits theaters Friday. Turteltaub dishes about what it was like to work with the A-listers.

"It's sort of a race between Kevin Kline and Morgan Freeman," says Turteltaub. "I wasn't surprised by how fun and funny Kevin was; I wasn't expecting Morgan Freeman to be as funny as he is."

Which star was the serious one on set?

"De Niro, oddly enough, is the cool, quiet loner type who is just very gentle and very shy. So it's hard to say whether he's the dark serious brooding guy or just the sweet quiet guy." He adds, "Michael's actually the cheeriest of them all, by the way. And he's a bit of a mood-setter. That was his character, too — the leader of the pack — so he took that on as well. He's the one with the 'Atta-boys' and 'Let's get going.'"

Who's in the best shape?

"I have not met a more physically in-shape or fit person than Kevin Kline. It's remarkable. There's nothing that guy can't do."

Which one would he work again with in an instant?

"If I'm smart, I won't mention just one."

Which one was most likely to forget lines?

"None of them! They may forget where they left their shoes, but the dialogue was fine."